Adaptive speciation: the role of natural selection in mechanisms of geographic and non-geographic speciation

Abstract

Recent discussion of mechanism has suggested new approaches to several issues in the philosophy of science, including theory structure, causal explanation, and reductionism. Here, I apply what I take to be the fruits of the Ônew mechanical philosophyÕ to an analysis of a contemporary debate in evolutionary biology about the role of natural selection in speciation. Traditional accounts of that debate focus on the geographic context of genetic divergencenamely, whether divergence in the absence of geographic isolation is possible (or significant). Those accounts are at best incomplete, I argue, because they ignore the mechanisms producing divergence and miss what is at stake in the biological debate. I argue that the biological debate instead concerns the scope of particular speciation mechanisms which assign different roles to natural selection at various stages of divergence. The upshot is a new interpretation of the crux of that debate-namely, whether divergence with gene flow is possible (or significant) and whether the isolating mechanisms producing it are adaptive.

Adaptive speciation theory: a conceptual review

“…However, speciation is not initiated by selection, and selection only comes into play after parts of a population have become isolated due to external events. For this reason, we do not consider speciation via the classical model ‘adaptive’ and we reserve the term adaptive speciation to those events where directional forces like natural or sexual selection are really crucial for the initiation and completion of speciation (Baker 2005). On the other hand, our usage of ‘adaptive’ speciation is much broader than that of (Dieckmann et al 2004), who reserve the term for speciation driven by highly specific forms of natural selection (see Gavrilets 2005).…”

“…Being the elaboration of a conference talk, this contribution is biased to our own work, and it does not address important aspects, such as the explanatory power of speciation models when applied to well-studied real-world systems (cichlids: Lande et al 2001; Gavrilets et al 2007; sticklebacks: Berner et al 2008; guppies: Labonne and Hendry 2010; walking sticks: Nosil and Yukilevich 2008; snails: Sadedin et al 2009; sea urchins and abalone: Van Doorn et al 2001; palms: Gavrilets and Vose 2007). Throughout, we will focus on adaptive routes to speciation, that is, on speciation scenarios where the evolution of reproductive isolation and/or ecological differentiation is directly driven by selection (Baker 2005). …”

Modeling Evo-Devo: Broken Hierarchies and Multiple Scales of Organization and Complexity

“…The main speciation models in biology are the allopatric, sympatric, and peripatric depending on the way the new species is originated from the parental one. However, speciation by other mechanisms, such as hybridization, is also possible [80], and it is still unknown the relative importance of each model of speciation [81].…”

OMEGA one multi ethnic genetic approach

“…We translate the biologic concepts of genetic isolation (a characteristic of populations with scarce genetic interchange) and genetic convergence (the process of acquisition of the same biological trait in unrelated populations) into an algorithmic approach. As for genetic isolation, we resort to the concept of speciation [1], the evolutionary process which gives rise to new biological species in connection with geographic isolation.…”